You have not mentioned what kind of RCM you are using but may I suggest taking your brush and going the opposite direction with the cleaning fluid and the rinse.
If you have access to a Spin Clean record cleaner, this is one of those times that they work very well. I use an eye dropper to apply the company specified amount of fluid over the entire surface of both pads. By applying the fluid at the top and bottom of the pads, and the remainder through out the centre of the pads, the lead in portion of the record gets much cleaner. I then go 30 spins in each direction. 15 right, 15 left, 15 right, and 15 left.It's the reversal of the brushes that really gets the gunk out of the grooves.
I have a vacuum RCM, but I still use the Spin Clean first to knock the bark off'em.
If you have access to a Spin Clean record cleaner, this is one of those times that they work very well. I use an eye dropper to apply the company specified amount of fluid over the entire surface of both pads. By applying the fluid at the top and bottom of the pads, and the remainder through out the centre of the pads, the lead in portion of the record gets much cleaner. I then go 30 spins in each direction. 15 right, 15 left, 15 right, and 15 left.It's the reversal of the brushes that really gets the gunk out of the grooves.
I have a vacuum RCM, but I still use the Spin Clean first to knock the bark off'em.